This proposal is for continuation of support for a 10-bed General Clinical Research Center and its associated laboratory in a large medical center for children closely affiliated with the Harvard Medical School, comprising 343 beds, with approximately 12,000 admissions and 160,000 outpatient visits per year. The research proposed, utilizing the facilities of the Clinical Research Center, will be carried out by members of the full-time staff from the Departments of Medicine, Cardiology, Neurology, Neurosurgery, Ophthalmology, Psychiatry, Surgery and Cardiovascular Surgery. Clinical investigations have as their goals the sharpening of methods of assessment, the deepening of understanding of fundamental processes at a molecular and cellular level, and improvement of the treatment of the following groups of disorders in children: immunodeficiency states, disturbances of complement metabolism, collagen diseases; bone marrow transplantation, hemoglobinopathies and red cell disorders; leucocyte and platelet dysfunction, disorders of neuroendocrine function, testicular development and metabolism of steroid hormones, hypoglycemic states and complications of diabetes mellitus; inflammatory bowel disease, liver disease and bile acid metabolism; disorders of lipid metabolism; the nephrotic syndrome and glomerular disease; Kartagener's syndrome; cystic fibrosis; essential hypertension and the use of extracorporeal oxygenation in pulmonary insufficiency.